RESUMO
BACKGROUND: Several lines of evidence approve that innate and adaptive immunity play key roles in the defense against visceral leishmaniasis (VL). The polymorphism within the cytotoxic T lymphocyte antigen 4 (CTLA-4) gene alters its expression. OBJECTIVES: The main aim of this study was to evaluate the polymorphism within the +49 position of the CTLA-4 gene of Iranian patients with VL in comparison with healthy controls. MATERIALS AND METHODS: In this cross-sectional study, 88 patients with clinical presentations of VL, who were seropositive for Leishmania (group 1), 86 patients without clinical presentations but seropositive (group 2), and 115 healthy controls (group 3) were assessed with respect to the CTLA-4 +49A/G polymorphism, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The anti-Leishmania antibody titration was evaluated using an immunofluorescence method. RESULTS: Our results indicated that both CTLA-4 +49A/G polymorphisms were significantly associated with VL. CONCLUSIONS: According to the results, the polymorphisms within the +49 position of CTLA-4 can be associated with VL and may be considered as risk factors for the disease.
RESUMO
CONTEXT: Toll-like receptors (TLRs) play crucial roles in immune responses, especially innate immunity, against viral infections. Toll-like receptor 9 recognizes intracellular viral double-strand DNA, which leads to the activation of nuclear factor B (NF-κB) through the myeloid differentiation primary response 88 (MYD88) pathway. Defects in the expression of TLR9 and its signaling molecules may cause attenuated immune responses against hepatitis B virus. OBJECTIVE: To determine expression levels of TLR9 messenger RNA along with MYD88, interleukin 1 receptor-associated kinase 1 (IRAK1), tumor necrosis factor receptor-associated factor 6 (TRAF6), and NF-κB in the peripheral blood mononuclear cells obtained from chronic hepatitis B virus (CHB)-infected patients. DESIGN: In this study, 60 CHB patients and 60 healthy controls were recruited and the expression of TLR9 and its downstream signaling molecules was examined by real-time polymerase chain reaction techniques using ß-actin as a housekeeping gene. RESULTS: Our results showed that expression of TLR9, MYD88, IRAK1, TRAF6, and NF-κB in peripheral blood mononuclear cells of CHB patients was significantly decreased in comparison with healthy controls. CONCLUSIONS: According to our results, it appears that CHB patients are unable to appropriately express genes in the TLR9 pathway, which may impede immune responses against hepatitis B virus infection. These results suggest a mechanism that may partially explain the fact that immune responses are disrupted in CHB patients.
Assuntos
Hepatite B Crônica/genética , Hepatite B Crônica/imunologia , Receptor Toll-Like 9/genética , Adulto , Estudos de Casos e Controles , DNA Viral/sangue , Regulação para Baixo , Feminino , Vírus da Hepatite B/genética , Vírus da Hepatite B/imunologia , Hepatite B Crônica/virologia , Humanos , Imunidade Inata/genética , Quinases Associadas a Receptores de Interleucina-1/genética , Masculino , Pessoa de Meia-Idade , Fator 88 de Diferenciação Mieloide/genética , NF-kappa B/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais , Fator 6 Associado a Receptor de TNF/genética , Carga ViralRESUMO
OBJECTIVES: Toxoplasma gondii is a worldwide prevalent zoonotic parasite which causes toxoplasmosis. An appropriate vaccine for animals could interrupt the circle between animals and humans. Our previous study showed that excreted/secreted antigens (E/SA), derived from the peritoneum of mice infected with T. gondii tachyzoites could be considered as a good candidate for animal vaccination. Interleukin-10 (IL-10) inhibits proliferation of B and T lymphocytes and induces homeostasis in immune system responses. However, since IL-10 has also been shown to suppress the killing of T. gondii by human macrophages, the aim of this study was to evaluate IL-10 serum levels after vaccination with T. gondii E/SA prepared in vivo. METHODS: T. gondii tachyzoites were inoculated in the peritoneum of mice and harvested E/SA were used as a vaccine, with and without adjuvant, in T. gondii infected and un-infected mice. IL-10 serum levels were evaluated using the ELISA technique. RESULTS: The data showed that although serum levels of IL-10 were not changed at the early phases, they were elevated at the end phases of vaccination with T. gondii E/SA. CONCLUSION: Based on these and our previous results, it can be concluded that in vivo prepared T. gondii E/SA could be considered as a good candidate for animal vaccination.